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Yellowing disease of tomato caused by Tomato chlorosis virus newly recognized in Japan Полный текст
2010
Hirota, Tomoki | Natsuaki, Tomohide | Murai, Tamotsu | Nishigawa, Hisashi | Niibori, Kenji | Goto, Kakushi | Hartono, Sedyo | Suastika, Gede | Okuda, Seiichi
In 2008, virus-like symptoms of yellowing, interveinal chlorosis, leaf curling and necrotic fleck were observed on greenhouse-tomato plants (Solanum esculentum) in Tochigi Prefecture. The symptomatology and the characteristics of the causal agent such as whitefly transmissibility and particle morphology are similar to those for Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV), species of the genus Crinivirus in the family Closteroviridae. Sequencing of reverse transcription-polymerase chain reaction (RT-PCR) products using the degenerate primers for heat shock protein 70 homolog genes of closteroviruses and specific primers for TICV and ToCV indicated that the virus was ToCV, that has not previously been reported in Japan.
Показать больше [+] Меньше [-]Foot rot of tomato [Lycopersicon esculentum], a new disease in Japan, caused by Fusarium solani, f. sp. eumartii
2010
Nakayama, K., Tochigi-ken. Agricultural Experiment Station, Utsunomiya (Japan) | Aoki, T.
Foot rot of tomato plants (Lycopersicon esculentum Mill.), observed in Tochigi Prefecture in May and June 2004, was characterized by discoloration of main root and wilt. Fungal strains that were isolated from symptomatic tissue, caused the same symptoms on tomato plants after artificial inoculations with the isolates. On the basis of morphological and molecular analyses, together with the pathogenicity tests, the fungus was identified as Fusarium solani f. sp. eumartii. In this report of foot rot disease of tomato caused by F. solani f. sp. eumartii in Japan, we propose the Japanese name 'Fusarium kabugusare-byo' of tomato.
Показать больше [+] Меньше [-]The first report of tomato foot rot caused by Rhizoctonia solani AG-3 PT and AG-2-Nt and its host range and molecular characterization Полный текст
2010
Misawa, Tomoo | Kuninaga, Shiro
Foot rot of mature tomato plants was found in four cities of Hokkaido, Japan, from 2004 to 2007. Six of eight isolates obtained from damaged tissues were identified as Rhizoctonia solani anastomosis group (AG)-3, and the remaining two isolates belonged to AG-2-1. We compared these isolates with nine reference isolates including the different subgroups in AG-3 (PT, TB and TM) and AG-2-Nt (pathogen of tobacco leaf spot) within AG-2-1 in terms of pathogenicity to tomato, tobacco and potato. All eight isolates caused foot rot on tomato. The six AG-3 isolates caused stem rot on young potato plants. While, all reference isolates of AG-3 PT causing stem rot of young potato plants incited foot rot on tomato. The two AG-2-1 isolates and an AG-2-Nt reference isolate caused severe leaf spot on tobacco leaves. The sequences of rDNA- ITS region and rDNA-IGS1 region of the AG-3 isolates showed high similarity to that of AG-3 PT isolates. Phylogenetic tree based on ITS and IGS1 regions of rDNA indicated that the AG-2-1 isolates from tomato formed a single clade with AG-2-Nt isolates and that they were separate from Japanese AG-2-1 isolates (culture type II). Pathogenicity tests and DNA sequence evaluation of the causal fungi revealed that the present isolates of AG-3 and AG-2-1 belonged to AG-3 PT and AG-2-Nt, respectively. This is the first report of tomato foot rot caused by R. solani in Japan.
Показать больше [+] Меньше [-]Uji Ketahanan Beberapa Varietas Tomat terhadap Penyakit Layu Fusarium (Fusarium oxysporum f. sp. lycopersici) Полный текст
2010
Chamzurni, Tjut | Ulim, M. Abduh | Dianur, Edi
Resistency of Tomatoes Varieties on Fusarium wilt Disease (Fusarium oxysporum f. sp. lycopersici)ABSTRACT. Tomato plants are herbaceous annual plant, having hermaphrodite flowers and are suitable to be planted in a cold area. Wilt disease is one of the important disease of tomato plants which is caused by Fusarium oxysporum f. sp. lycopersici (fol). This disease can cause a great loss to the tomato producing in many regions in the world 20%-30%. A study has been conducted the resistance of several varieties of tomato plants against Fusarium wilt disease caused by Fusarium oxysporum f. sp. lycopersici. The tomato varieties observed were Local Aceh, Jelita, Permata, Sakata and Lentana. The results showed that Local Aceh variety and Jelita variety were highly resistant to Fusarium wilt disease. The other 3 varieties showed a lower level of resistance to the wilt disease compared to those of Local Aceh and Lentana variety.
Показать больше [+] Меньше [-]Yellowing disease of tomato [Lycopersicon esculentum] caused by Tomato chlorosis virus newly recognized in Japan
2010
Hirota, T., Utsunomiya Univ. (Japan). Faculty of Agriculture | Natsuaki, T. | Murai, T. | Nishigawa, H. | Niibori, K. | Goto, K. | Hartono, S. | Suastika, G. | Okuda, S.
In 2008, virus-like symptoms of yellowing, interveinal chlorosis, leaf curling and necrotic fleck were observed on greenhouse-tomato plants (Solanum lycopersicum) in Tochigi Prefecture. The symptomatology and the characteristics of the causal agent such as whitefly transmissibility and particle morphology are similar to those for Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV), species of the genus Crinivirus in the family Closteroviridae. Sequencing of reverse transcription- polymerase chain reaction (RT-PCR) products using the degenerate primers for heat shock protein 70 homolog genes of closteroviruses and specific primers for TICV and ToCV indicated that the virus was ToCV, that has not previously been reported in Japan.
Показать больше [+] Меньше [-]Allergenicity Assessment of Genetically Modified Cucumber Mosaic Virus (CMV) Resistant Tomato (Solanum lycopersicon) Полный текст
2010
Lin, Chih-Hui | Sheu, Fuu | Lin, Hsin-Tang | Pan, Tzu-Ming
Cucumber mosaic virus (CMV) has been identified as the causal agent of several disease epidemics in most countries of the world. Insect-mediated virus diseases, such as those caused by CMV, caused remarkable loss of tomato (Solanum lycopersicon) production in Taiwan. With expression of the CMV coat protein gene (Cmvcp) in a local popular tomato cultivar L4783, transgenic tomato line R8 has showed consistent CMV resistance through T0 to T8. In this report, the allergenicity of the CMV coat protein (CMV cp) expressed in transgenic tomato R8 was assessed by investigation of the expression of the transgene source of protein, sequence similarity with known allergens, and resistance to pepsin hydrolysis. There is no known account for either the CMV or its coat protein being an allergen. The result of a bioinformatic search also showed no significant homology between CMV cp and any known allergen. The pepsin-susceptible property of recombinant CMV cp was revealed by a simulated gastric fluid (SGF) assay. Following the most recent FAO/WHO decision tree, all results have indicated that CMV cp was a protein with low possibility to be an allergen and the transgenic tomato R8 should be considered as safe as its host.
Показать больше [+] Меньше [-]First report of bacterial speck of tomato caused by Pseudomonas syringae pv. tomato race 1 in Portugal Полный текст
2010
Cruz, L. | Cruz, J. | Eloy, M. | Oliveira, Helena | Vaz, H. | Tenreiro, R.
Protected and open field tomato crops are economically important for Portuguese agriculture. In 1983, Pseudomonas syringae pv. tomato (Okabe, 1933) Young, Dye & Wilkie, 1978 was first reported affecting protected crops (3) and then later under open field conditions (1). In the 2009 spring/summer season, several outbreaks of bacterial speck of tomato showing an unusual degree of severity were observed in open fields from the Tagus Valley Region
Показать больше [+] Меньше [-]Morphological and molecular identification of Colletotrichum acutatum from tomato fruit
2010
Živković, S., Institute for Plant Protection and Environment, Belgrade (Serbia) | Stojanović, S., Institute for Plant Protection and Environment, Belgrade (Serbia) | Ivanović, Ž., Institute for Plant Protection and Environment, Belgrade (Serbia) | Trkulja, N., Institute for Plant Protection and Environment, Belgrade (Serbia) | Dolovac, N., Institute for Plant Protection and Environment, Belgrade (Serbia) | Aleksić, G., Institute for Plant Protection and Environment, Belgrade (Serbia) | Balaž, J., Faculty of Agriculture, Novi Sad (Serbia)
In Serbia, the occurrence of anthracnose on tomato fruit has been recorded during the last several years. Typical fruit symptoms include dark, sunken, and circular lesions with orange colonial masses. Pathogen isolates were obtained from a diseased tomato fruits, on PDA medium forming a white to gray colonies. The cultures developed black acervuli around the center of the colony. Conidia were hyaline, aseptate, and fusiform or rarely cylindrical. Appressoria were smooth, simple, clavate to ovate, and varied from light to dark brown. Pathogenicity tests with representative isolates were conducted on symptomless, detached tomato fruits. All tested isolates caused anthracnose lesions on tomato fruit after 7 days of incubation. Koch's postulates were fulfilled by reisolation from incubated tomato fruits. PCR analysis of genomic DNA from tomato isolates resulted in an amplification product of 490 bp, specific for C. acutatum, further confirming the identity of the pathogen. Based on morphological and molecular characteristics, the isolates from tomato fruit were determined as Colletotrichuma acutatum
Показать больше [+] Меньше [-]First Report of Bacterial Spot of Tomato Caused by Xanthomonas gardneri in Pennsylvania Полный текст
2010
Kim, S.H. | Olson, T.N. | Peffer, N.D. | Nikolaeva, E.V. | Park, S. | Kang, S.
Recent investigation of bacteria isolated from samples submitted to the Plant Disease Diagnostic Laboratory, Pennsylvania Department of Agriculture indicated that in 1995, Xanthomonas gardneri (ex Sutic 1957) (2) caused a leaf spot on tomato plants (Lycopersicon esculentum Mill.). In 1995, we examined 185 tomato and 36 pepper samples (13 field, 2 garden center, 38 greenhouse, 4 residence, 16 field-grown transplant, and 148 greenhouse-grown transplant samples). A processing company representative collected samples showing symptoms of bacterial spot of tomato on a hybrid, whole pack processing tomato, from a 16-ha field in Northumberland County, PA exhibiting almost 50% crop infection. Symptoms consisted of circular- to irregularly shaped, dark brown spots, <5 mm in diameter, and frequently with chlorotic haloes on leaves and stems. The center of a spot may be raised and scabby. Several spots on a single leaflet may coalesce and a portion or the entire leaflet may turn yellow or die. These symptoms were indistinguishable from those of bacterial spot caused by X. euvesicatoria, X. vesicatoria, and X. perforans. Bacterial streaming from lesions was evident under dark-field microscopy. Aerobic, gram-negative, yellow-pigmented, mucoid bacteria were isolated from the leaf spots and purified and stored in nutrient broth with 10% glycerol at –80°C. The 16S rRNA gene from a strain (PDA80951-95) typical of the cultures from these samples was sequenced (GenBank Accession No. GU573763). A BlastN search of GenBank revealed 100% nucleotide identity with the type strain of X. gardneri (XCGA2; No. AF123093). This strain also exhibited repetitive sequence-based (rep)-PCR profiles (4) identical to profiles of X. gardneri type strain XCGA2 DNA and produced a approximately 425-bp PCR product with BSX primers, a genetic marker indicative of X. gardneri (1). The strain was not amylolytic or pectolytic (2) and failed to utilize maltose, gentiobiose, and melezitose (3). For pathogenicity tests, inoculum was grown in nutrient broth with shaking for 24 h at 28°C. Inoculum was centrifuged, resuspended in sterile tap water, and adjusted to 2.5 × 10⁸ CFU/ml. Lower leaf surfaces of tomato (cvs. Bonnie Best and Walter) and pepper (cvs. California Wonder and Early Niagara) plants were gently rubbed with sterile cheesecloth that was moistened with the inoculum. Strain PDA80951-95 caused leaf spots, with chlorotic haloes and occasional coalescence on both tomato and pepper, within 2 weeks at 15 s of mist per 20 min at 20 to 35°C in a secured greenhouse chamber. X. gardneri was only reisolated from symptomatic plants and its identity was confirmed by rep-PCR and absence of amylolytic and pectolytic activities. Negative controls consisting of X. campestris pv. campestris and sterile tap water did not show symptoms. A known type strain of X. gardneri was not included as a positive control for pathogenicity studies because this species is not known to occur in the United States (2). To our knowledge, this is the first report of bacterial spot on tomato plants caused by X. gardneri in Pennsylvania and the United States. Since the first occurrence in 1995, bacterial spot caused by X. gardneri reoccurred in Pennsylvania tomato fields in 2001 and consecutively from 2003 to 2009.
Показать больше [+] Меньше [-]Morphological and Molecular Identification of Colletotrichum acutatum from Tomato Fruit Полный текст
2010
Svetlana Živković | Saša Stojanović | Žarko IVanović | Nenad Trkulja | Nenad Dolovac | Goran Aleksić | Jelica Balaž
Colletotrichum gloeosporioides, Colletotrichum acutatum, Colletotrichum coccodes, and Colletotrichum dematium are the four main species of Colletotrichum that cause tomato anthracnose. In Serbia, the occurrence of anthracnose on tomato fruit has been recorded during the last several years. Typical fruit symptoms include dark, sunken, and circular lesion with orange conidial masses. Pathogen isolates were obtained from a diseased tomato fruits, on PDA medium forming a white to gray colonies. The cultures developed black acervuli around the center of the colony. Conidia were hyaline, aseptate, and fusiform or rarely cylindrical. Appressoria were smooth, simple, clavate to ovate, and variedfrom light to dark brown. Pathogenicity tests with representative isolates were conducted on symptomless, detached tomato fruits. All tested isolates caused anthracnose lesions on tomato fruit after 7 days of incubation. Koch’s postulates were fulfilled by reisolationfrom inoculated tomato fruits. PCR analysis (using species-specific primer pair, CaInt2/ITS4) of genomic DNA from tomato isolates resulted in an amplification product of 490 bp, specific for C. acutatum, further confirming the identity of the pathogen. Based onmorphological and molecular characteristics, the isolates from tomato fruit were determined as C. acutatum.
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